1. Field of the Invention
The present invention relates to a cutter blade assembly, and in particular, a cutter blade assembly for the efficient production of carrot sticks.
2. Description of the Related Art
Many vegetables and fruits are processed and preserved prior to sale to extend their useable shelf life. Most are cut into smaller edible sizes and shapes during processing, and many are cut into small cross-sectional shapes to minimize cooking time. It is well known that vegetables in particular lose some of their nutritional value when processed, stored and cooked prior to consumption. Accordingly, many vegetables are harvested, washed, packaged and quickly shipped to market to be sold fresh. It is desirable that a minimum of processing be done without adversely affecting the shelf-life of the product. Cutting of the vegetable into edible sized portions is then performed by the consumer just prior to consumption.
Root crops such as carrots and potatoes are typically cut into stick form, using a rectilinear array of strip knives, or blades, to form sticks of rectangular or square cross section. The outer crescent-shaped portions of the carrot or potato which are smaller than the minimum acceptable size are then discarded or used for other purposes, such as making juices or soups.
Methods of making staged cuts of vegetables to more efficiently utilize the vegetable are known. For example, U.S. Pat. No. 4,372,184 discloses a cutting assembly for making successive, or staged, cuts to a potato to cut two different shapes of potato products. In this assembly, a first core knife cuts a plurality of outer strips from the potato, leaving a cylindrical core and a second set of strip knives cuts the cylindrical core into pieces of substantially constant cross-section. However, this patent does not disclose successively cutting substantially identically-shaped finished end products from a vegetable.
Recent advances in the processing of fresh carrots, typified by U.S. Pat. Nos. 4,919,948, 4,855,153, 4,670,275 and 4,808,420, have extended the shelf life of carrots and made possible the factory processing of carrot sticks, which may then be shipped fresh to the retail market. These patents describe methods of prolonging the shelf-life of root crops by a mild heat treatment to reduce microflora, rapid cooling and alternate methods to prevent microbial recontamination and maintain the root crop in a viable condition. Carrot sticks processed in the manner disclosed in these patents have been successfully marketed in restaurants. To be commercially successful, carrot sticks must meet commercial requirements for size, taste, texture and shelf-life.
A carrot has a fleshy, outer portion and a more fibrous inner core portion. Carrot sticks comprised entirely of the inner core portion are commercially undesirable because the fibrous inner core tends to have less flavor and to be tougher and more difficult to chew. However, carrot sticks which are comprised of at least about half fleshy, outer portion and at most about half inner core portion are acceptable in taste and texture. Carrots grow to different diameters and contain different percentages of inner core, depending upon growing conditions, such as soil nutrients, temperature, amount of sunshine and amount of rainfall or irrigation.
Cutting a vegetable which has a round cross-section, such as a carrot, into rectangular cross-section portions with conventional rectilinear blade arrays is inherently inefficient in yield. Some carrot sticks of unacceptably small cross-section are produced. Carrot sticks of acceptable cross-section at their larger end may taper to a point or a thin triangular cross-section at their smaller end. Such carrot sticks are commercially unacceptable because their thin cross-section causes them to dry out and thus shortens their shelf-life. Additionally, properly sized, but commercially unacceptable carrot sticks comprised of all or mostly inner core may be produced. The sticks predominantly comprised of core must then be separated from the acceptable sticks. Although proper positioning of the carrot relative to the rectilinear blade array can reduce the percentage of unacceptable carrot sticks produced, a better, more efficient method of producing carrot sticks is needed.